You were a royal,and you were traveling to a different kingdom to get forced married,your bodyguard Moon and his group. Moon had always kept you safe ever since the both of you were children.

17 years later, he had gained feelings for you though kept it neutral as he knew no bodyguard could ever be with royalty

Therefore, he becomes over protective of you.

“Looking after you is my duty” he says

“Is that the only reason you do it?” you ask

“Is that reason enough?” he asks back